Robin Williams and Michael J. Fox, two aging stars of 1980s TV, squared off with comedy premieres Thursday night. And the first round went to .... Williams.

CBS' 9 p.m. sitcom "The Crazy Ones" - which has the former "Mork & Mindy" star playing a zany ad whiz who runs an agency with his daughter (Sarah Michelle Gellar) - rounded up 15.6 million total viewers, according to Nielsen.

That makes it the most-watched new show of the fall TV season so far.

Meanwhile, NBC at 9 p.m. aired a one-hour premiere special of "The Michael J. Fox Show," but the results weren't nearly as promising. "Fox" - which features the former "Family Ties" star as a newsman on the road to a comeback after a Parkinson's diagnosis - gathered just 7.3 million, or less than half the audience for Williams' effort.

The results were a tough blow for NBC, which hoped Fox could recover some of the ratings magic he enjoyed on "Family Ties" and "Spin City." But his new show gave NBC its worst Thursday fall comedy debut ever in the crucial adults aged 18 to 49 demographic, with an anemic 2.1 rating.

As for Williams, he's lucky that Fox was around to make his ratings look great. Because if you examine the numbers for "The Crazy Ones" a little more closely, they don't look so hot either. Williams was just the beneficiary of some clever scheduling.

CBS wisely placed "The Crazy Ones" after two back-to-back episodes of its smash "The Big Bang Theory." This gave the Williams show a huge lead-in, with the second helping of "Big Bang" delivering 19.5 million viewers.

But "The Crazy Ones" didn't do a very good job holding on to that big audience, retaining just more than two-thirds of the young adults who showed up for "Big Bang." Generally, any retention figure of less than 80% is cause for concern.

However, Williams has plenty more time to prove his show's worth. For Fox, however, the outcome already looks bleak.